1. Field of the Invention
This invention relates to a method of manufacturing a liquid discharging head for use in an ink jet recording process or the like, and particularly aims at an improvement in the discharging performance of a so-called side shooter type head from which liquid droplets are discharged in a direction perpendicular to a substrate on which an energy generating element is formed.
2. Related Background Art
As a liquid discharging head for discharging liquid, there is known one which, as disclosed in U.S. Pat. No. 6,155,673, discharges an ink droplet by giving heat energy to a heat generating resistance member to thereby film-boil ink, and communicating a produced bubble with the atmosphere. As a schematic manufacturing method for realizing the above-described ink jet recording head, there is known a method disclosed in U.S. Pat. No. 5,478,606.
This method has the following steps:
(1) The step of forming an ink flow path pattern with a soluble resin on a substrate on which an ink discharge pressure generating element is formed;
(2) The step of dissolving a coat resin in a solvent, and solvent-coating a soluble resin layer with this to thereby form a nozzle-constituting resin layer providing an ink flow path wall on the soluble resin layer;
(3) The step of forming an ink discharge port in the nozzle-constituting resin layer above the ink discharge pressure generating element; and
(4) The step of eluting the soluble resin layer.
Now, in the above-described ink jet recording head, the shape of the ink flow path determines the discharge amount, the discharge direction and the discharge speed of an ink droplet, and it greatly affects the quality of print. Here, observing the cross-section of the ink jet recording head formed by the method disclosed in U.S. Pat. No. 5,478,606, a minute projection-shaped object is sometimes observed near the interface between the soluble resin layer and the nozzle-constituting resin layer. Further, the phenomenon that the discharge direction of the ink droplet flying from a discharge port surface is bent by this minute projection-shaped object, whereby a printed image is deteriorated, has been observed.